This invention is directed to an apparatus for pre-folding the top panels of a gable-top carton. More specifically, the invention pertains to a top pre-folding apparatus for pre-folding the top gable panels of a carton having an extended top panel.
Gable top cartons are in widespread use. Such cartons have been known for most of the twentieth century. These cartons have gained widespread acceptance and popularity as cartons for traditional products, such as liquid food products, for example milk and juice. These cartons are also used for packaging non-liquid food items, such as dried and particulate soups and for non-food items, such as laundry detergent.
Early traditional gable top cartons included a pour-spout that was formed by opening a portion of one side of the gable. While this configuration was and still is widely accepted, one drawback is that resealability of the carton is limited. That is, while the gable can be xe2x80x9crefoldedxe2x80x9d to close the carton, actual sealing to reduce exposure to the environment, is quite limited. To this end, improvements to such gable top cartons are ongoing.
In one such improvement, a spout is provided on one of the gable panels and is integrally sealed thereto. The spout provides ready access to the packaged product. In a xe2x80x9ctraditionalxe2x80x9d spout arrangement, an opening is formed in the gable panel and a plastic or like spout is welded or sealed to the panel. A cap, such as a threaded closure or a hinged closure is fitted to the spout to provide resealability of the container. Such spouts have come into widespread use and ready acceptance for their ease of access to the product and their ability to help maintain product freshness.
In still another enhancement to the gable top carton, it has been found that it is desirable to provide an extended gable or top panel. The extended panel can provide additional area for marketing or advertising print and can be configured to permit the use of larger spouts and or caps. Use of larger spouts can be particularly advantageous for more viscous or solids-containing products. Additionally, these extended top panels provide an aesthetic appeal and distinctive appearance compared to xe2x80x9ctraditionalxe2x80x9d gable top cartons. To this end, these enhanced designs have been found to be desirable for all packaged products.
Due to the nature of these extended top panels, it has been found that the typical pre-folding arrangements for pre-folding the top panels and in particular the extended gable panel, do not produce the desired pre-folds of these panels. It has also been found that the known pre-folders may not properly pre-fold the various carton top panels and that xe2x80x9cdimplesxe2x80x9d or indented regions can form at various panel junctures.
Accordingly, there exists a need for an improved top panel pre-folder apparatus for use with gable top cartons. This is particularly true for gable top cartons having extended or enlarged top panels. Desirably, such a top pre-folder permits the forming of the necessary folds in the enhanced gable configuration.
A top panel pre-folder for a form, fill and seal packaging machine for forming, filling and sealing extended top panel gable top cartons provides the requisite forming or pre-folding of the various top panel creases necessary for the enhanced gable configuration. The machine defines a processing path along which the cartons are conveyed. The top pre-folder is disposed subsequent to bottom panel folding and sealing, and prior to a filling station along the machine processing path.
The gable top carton includes a sealed bottom, a pair of vertical side panels, and a pair of gable side panels. Each of the gable side panels is contiguous with a respective one of the vertical side panels to define a pair of gable side panel/vertical side panel junctures. In the extended top panel arrangement, the gable side panel/vertical side panel junctures are formed at an angle relative to the sealed bottom (e.g., at an angle relative to the horizontal).
The pre-folder includes a pair of pivotal arms and a mandrel positioned along the processing path. The mandrel is movable between a position above the carton and a position interior of the carton as the carton moves along the processing path. The arms are disposed on opposing sides of the mandrel and are mounted transverse to the processing path. Each arm pivots about an axis. The arms each include a flap mounted thereto.
The flaps are mounted to the arms to rotate through an arcuate path toward and away from the mandrel. Preferably, the flaps are triangular in shape and include a raised portion extending from a face of the flap at a lower region of the flap. Most preferably, the flaps are mounted to the arm, spaced from the axis of rotation of the arm.
The arms pivot to move the flaps into engagement with the gable side panels. This infolds the gable side panels inwardly over the mandrels. The flap raised portions contact the gable side panels at about the gable side panel/vertical side panel junctures. This provides a precise pre-folding or xe2x80x9cbreakingxe2x80x9d of the carton crease lines to impart clean, distinct fold lines in the formed and sealed carton.
In a preferred embodiment, the pivotal arm axes are disposed at an angle relative to the horizontal. Most preferably, the pivotal arm axes are disposed at an angle about equal to the angle at which the gable side panel/vertical side panel junctures are formed relative to the horizontal.
In a present machine, each mandrel defines a pair of head portions and the head portions each define a fold edge. In this arrangement, the fold edges are formed generally parallel to their respective pivotal arm axes.
To meet the need for increase operating speeds and processing efficiency, the machine can include multiple pairs of pivotal arms and mandrels. In such an arrangement, the pairs of arms can be disposed on opposing sides of the processing path and their associated mandrels can be positioned directly above the processing path.
In a current embodiment, each pair of pivotal arms and its associated mandrel are carried by a reciprocating carriage. The carriage provides for unitarily moving the arms and mandrel into and out of engagement with the cartons. The carriages carrying the arms and mandrels are configured to reciprocate vertically to move the arms and mandrels into and out of engagement with the cartons below.
Other features and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings and the appended claims.